Portable radiotelephones are becoming a preferred mode of communication which is increasingly relied on, for example, by business users when they are away from the office. Conveniently, increasing numbers of radio-towers and satellite systems are each increasing a user's ability to be available for almost constant communication even in rural or remote areas. This increased popularity produces a sophisticated consumer who demands sometimes competing product specifications or criteria. For example, desired performance parameters typically include improved signal quality, durability, and superior aesthetic qualities all the while shrinking the size of the portable radiotelephone to improve its transportability.
In operation, portable radiotelephones transmit and receive signals from a source such as a transmission tower or satellite. This tower or satellite is typically positioned at a site which is remote from the user of the portable radiotelephone. It will be appreciated that generally the further away a signal is from its transmission source, the weaker the signal and the higher the potential for noise to be introduced into the signal. Thus, a successful portable radiotelephone typically must have the ability to detect, receive, and relay a potentially weak distant signal without increasing the power in the phone to extreme levels while also shielding the signal from undesirable noise contamination.
Further, as noted above, many of the more popular hand-held telephones are undergoing miniaturization. Indeed, many of the contemporary models are only 11-12 centimeters in length. While the aesthetic features and transportability of the radiotelephones can be improved by these reduced dimensions, the miniaturized telephone may further complicate the ability of the telephone to adequately increase the signal to compensate for transmittal distances. This is especially true for a satellite communication based system.
In the past, portable satellite radiotelephones have employed helix antennas such as quadrafillar helix antennas to help achieve acceptable signal quality. Quadrafillar helix antennas utilize four spaced-apart filament elements which are wound around an antenna's surface. Preferably, the filament elements are positioned to be equally spaced around the circumference of the antenna. Unfortunately, although these type of antennas may provide adequate performance, there remains a need to further improve the signal quality while also providing a durable, aesthetically pleasing radiotelephone.